Formation of Volatile Halogenated By-Products During the Chlorination of Oxytetracycline

Xu, Bin; Zhu, He-Zhen; Lin, Yi-Li; Shen, Kai-Yuan; Chu, Wen-Hai; Hu, Chen-Yan; Tian, Kang-Ning; Mwakagenda, Seleli Andrew; Bi, Xiang-Yu

Formation of Volatile Halogenated By-Products During the Chlorination of Oxytetracycline

2012

This study investigated the formation of volatile carbonaceous disinfection by-products (DBPs) and nitrogenous DBPs from chlorination of oxytetracycline. Six DBPs were identified including chloroform (CF), 1,1-dichloroacetone, 1,1,1-trichloroacetone (TCP), dichloroacetonitrile (DCAN), trichloroacetonitrile, and trichloronitromethane. DBP yields varied with different reaction conditions, including chlorine concentration, reacting time, pH, and bromide concentration. The highest DBP yields were found at Cl₂/C mass ratio and reaction time of 5 and 3âdays, respectively. The solution pH had significant influence on CF, DCAN, and 1,1,1-TCP formation. The concentration of CF increased with the increase of pH, while DCAN and 1,1,1-TCP yields were high at acidic pH and decreased greatly under alkaline conditions. In the presence of bromide, the DBP composition shifted to multiple bromide compounds, including bromodichloromethane, dibromochloromethane, bromoform, bromochloroacetonitrile, and dibromoacetonitrile.

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